...why thermal comfort should not be an afterthought. (read the first part of this interview here)

Mr. Bentz, you also focus on Aersulate. What makes this technology interesting for military and protective textiles?

Aersulate is a high-performance insulation technology based on aerogel. Aerogel is known for its extremely low thermal conductivity. The challenge has always been to bring this performance into textile structures in a practical and wearable way. With Aersulate, we can enable thin, flexible and high-performing insulation concepts. This is especially interesting for military applications because volume, weight and freedom of movement are always critical. If a jacket, glove or protective textile can be thinner while still offering strong insulation performance, this opens completely new design opportunities. The technology can also support multifunctional textile constructions. For example, it can be combined with different textile carriers, including solutions for protective or flame-resistant applications, depending on the construction and material concept.

Why is thin insulation such an important advantage?

In military clothing, bulk is a major issue. Thick insulation can restrict movement, increase pack volume and make layering more difficult. It can also interfere with equipment such as body armor, harnesses or backpacks. A thinner insulation concept can help designers create garments that are easier to wear, easier to pack and better suited to complex equipment systems. It can also support better fit and mobility. Another important point is performance under pressure. In real use, insulation is often compressed, for example at the shoulders under backpack straps, at the elbows, knees or seat areas. Many conventional insulation materials lose performance when compressed. Aersulate can help address this challenge by enabling insulation concepts that perform even in demanding constructions.

How does this connect to RCT values and measurable performance?

In technical textiles, performance must be measurable. RCT values are a key indicator for thermal resistance, showing how effectively a material slows down heat flow. With Aersulate, strong insulation performance can be achieved in very thin textile constructions. Depending on the article, Aersulate fabrics with a thickness of only 1.1 reach RCT values of 0.08, combined with low thermal conductivity values down to 0.028 W/mK. This gives product developers more freedom to reduce bulk, work with slimmer constructions or design advanced multilayer systems while still targeting measurable thermal performance. Aersulate also shows its strength under pressure. In a test with a 100 °C heating plate and a 5 kg weight applied to the fabric, the Aersulate felt reached only around 60 °C after 12 minutes, while a comparable felt without Aersulate reached around 75 °C. This makes Aersulate especially relevant for applications where insulation has to perform in limited space, under load or close to heat sources. For military and protective markets, measurable performance is essential. It is not enough for a material to feel good in a showroom. It has to deliver reliable benefits in demanding real-world conditions.

You mentioned flame-resistant constructions. How important is that for this target group?

It can be very important, depending on the application. Military and protective textiles often have to meet multiple requirements at once. Thermal comfort alone is not enough. A fabric may also need durability, flame resistance, abrasion resistance, breathability, low bulk or compatibility with other equipment. This is where textile engineering becomes interesting. Aersulate is not just an insulation material; it can be part of a broader construction concept. Depending on the textile carrier and system design, it can contribute to multifunctional fabrics that combine insulation with other protective properties. The future of military textiles is not one single function. It is the intelligent combination of functions in one system.

What is the biggest misconception about thermal comfort in protective clothing?

Many people still think of comfort as something secondary, something nice to have after protection and durability have been solved. But in demanding applications, comfort has a direct impact on the wearer. If a person overheats, sweats heavily or feels cold during low-activity phases, this creates additional stress. The body has to work harder to maintain balance. Over time, this can affect endurance, concentration and the overall ability to perform. Thermal comfort should therefore not be seen as a luxury. It is part of functional performance.

What message would you like to give to military equipment developers and textile engineers?

Do not look at thermal comfort as an afterthought. Consider it from the very beginning of product development. A garment or textile system can meet all formal requirements and still be uncomfortable in real use if the microclimate is not managed properly. Especially in military and protective applications, where equipment is worn for long periods and under high physical stress, this can make a major difference. Our message is simple: advanced thermal management can help create better conditions for the wearer. Less thermal stress, better comfort and more design freedom are not separate goals. They are part of the same performance story.